/*
 * This is an implementation of wcwidth() and wcswidth() (defined in
 * IEEE Std 1002.1-2001) for Unicode.
 *
 * http://www.opengroup.org/onlinepubs/007904975/functions/wcwidth.html
 * http://www.opengroup.org/onlinepubs/007904975/functions/wcswidth.html
 *
 * In fixed-width output devices, Latin characters all occupy a single
 * "cell" position of equal width, whereas ideographic CJK characters
 * occupy two such cells. Interoperability between terminal-line
 * applications and (teletype-style) character terminals using the
 * UTF-8 encoding requires agreement on which character should advance
 * the cursor by how many cell positions. No established formal
 * standards exist at present on which Unicode character shall occupy
 * how many cell positions on character terminals. These routines are
 * a first attempt of defining such behavior based on simple rules
 * applied to data provided by the Unicode Consortium.
 *
 * For some graphical characters, the Unicode standard explicitly
 * defines a character-cell width via the definition of the East Asian
 * FullWidth (F), Wide (W), Half-width (H), and Narrow (Na) classes.
 * In all these cases, there is no ambiguity about which width a
 * terminal shall use. For characters in the East Asian Ambiguous (A)
 * class, the width choice depends purely on a preference of backward
 * compatibility with either historic CJK or Western practice.
 * Choosing single-width for these characters is easy to justify as
 * the appropriate long-term solution, as the CJK practice of
 * displaying these characters as double-width comes from historic
 * implementation simplicity (8-bit encoded characters were displayed
 * single-width and 16-bit ones double-width, even for Greek,
 * Cyrillic, etc.) and not any typographic considerations.
 *
 * Much less clear is the choice of width for the Not East Asian
 * (Neutral) class. Existing practice does not dictate a width for any
 * of these characters. It would nevertheless make sense
 * typographically to allocate two character cells to characters such
 * as for instance EM SPACE or VOLUME INTEGRAL, which cannot be
 * represented adequately with a single-width glyph. The following
 * routines at present merely assign a single-cell width to all
 * neutral characters, in the interest of simplicity. This is not
 * entirely satisfactory and should be reconsidered before
 * establishing a formal standard in this area. At the moment, the
 * decision which Not East Asian (Neutral) characters should be
 * represented by double-width glyphs cannot yet be answered by
 * applying a simple rule from the Unicode database content. Setting
 * up a proper standard for the behavior of UTF-8 character terminals
 * will require a careful analysis not only of each Unicode character,
 * but also of each presentation form, something the author of these
 * routines has avoided to do so far.
 *
 * http://www.unicode.org/unicode/reports/tr11/
 *
 * Markus Kuhn -- 2003-05-20 (Unicode 4.0)
 *
 * Permission to use, copy, modify, and distribute this software
 * for any purpose and without fee is hereby granted. The author
 * disclaims all warranties with regard to this software.
 *
 * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
 */

#include <wchar.h>

#include "putty.h" /* for prototypes */

struct interval
{
    int first;
    int last;
};

/* auxiliary function for binary search in interval table */
static int bisearch(wchar_t ucs, const struct interval *table, int max)
{
    int min = 0;
    int mid;

    if (ucs < table[0].first || ucs > table[max].last)
        return 0;
    while (max >= min)
    {
        mid = (min + max) / 2;
        if (ucs > table[mid].last)
            min = mid + 1;
        else if (ucs < table[mid].first)
            max = mid - 1;
        else
            return 1;
    }

    return 0;
}

/* The following two functions define the column width of an ISO 10646
 * character as follows:
 *
 *    - The null character (U+0000) has a column width of 0.
 *
 *    - Other C0/C1 control characters and DEL will lead to a return
 *      value of -1.
 *
 *    - Non-spacing and enclosing combining characters (general
 *      category code Mn or Me in the Unicode database) have a
 *      column width of 0.
 *
 *    - SOFT HYPHEN (U+00AD) has a column width of 1.
 *
 *    - Other format characters (general category code Cf in the Unicode
 *      database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
 *
 *    - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
 *      have a column width of 0.
 *
 *    - Spacing characters in the East Asian Wide (W) or East Asian
 *      Full-width (F) category as defined in Unicode Technical
 *      Report #11 have a column width of 2.
 *
 *    - All remaining characters (including all printable
 *      ISO 8859-1 and WGL4 characters, Unicode control characters,
 *      etc.) have a column width of 1.
 *
 * This implementation assumes that wchar_t characters are encoded
 * in ISO 10646.
 */

int mk_wcwidth(wchar_t ucs)
{
    /* sorted list of non-overlapping intervals of non-spacing characters */
    /* generated by "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c" */
    static const struct interval combining[] = { { 0x0300, 0x0357 }, {
            0x035D,
            0x036F
        }, { 0x0483, 0x0486 }, { 0x0488, 0x0489 },
        { 0x0591, 0x05A1 }, { 0x05A3, 0x05B9 }, { 0x05BB, 0x05BD }, {
            0x05BF, 0x05BF
        }, { 0x05C1, 0x05C2 }, { 0x05C4, 0x05C4 }, {
            0x0600, 0x0603
        }, { 0x0610, 0x0615 }, { 0x064B, 0x0658 }, {
            0x0670, 0x0670
        }, { 0x06D6, 0x06E4 }, { 0x06E7, 0x06E8 }, {
            0x06EA, 0x06ED
        }, { 0x070F, 0x070F }, { 0x0711, 0x0711 }, {
            0x0730, 0x074A
        }, { 0x07A6, 0x07B0 }, { 0x0901, 0x0902 }, {
            0x093C, 0x093C
        }, { 0x0941, 0x0948 }, { 0x094D, 0x094D }, {
            0x0951, 0x0954
        }, { 0x0962, 0x0963 }, { 0x0981, 0x0981 }, {
            0x09BC, 0x09BC
        }, { 0x09C1, 0x09C4 }, { 0x09CD, 0x09CD }, {
            0x09E2, 0x09E3
        }, { 0x0A01, 0x0A02 }, { 0x0A3C, 0x0A3C }, {
            0x0A41, 0x0A42
        }, { 0x0A47, 0x0A48 }, { 0x0A4B, 0x0A4D }, {
            0x0A70, 0x0A71
        }, { 0x0A81, 0x0A82 }, { 0x0ABC, 0x0ABC }, {
            0x0AC1, 0x0AC5
        }, { 0x0AC7, 0x0AC8 }, { 0x0ACD, 0x0ACD }, {
            0x0AE2, 0x0AE3
        }, { 0x0B01, 0x0B01 }, { 0x0B3C, 0x0B3C }, {
            0x0B3F, 0x0B3F
        }, { 0x0B41, 0x0B43 }, { 0x0B4D, 0x0B4D }, {
            0x0B56, 0x0B56
        }, { 0x0B82, 0x0B82 }, { 0x0BC0, 0x0BC0 }, {
            0x0BCD, 0x0BCD
        }, { 0x0C3E, 0x0C40 }, { 0x0C46, 0x0C48 }, {
            0x0C4A, 0x0C4D
        }, { 0x0C55, 0x0C56 }, { 0x0CBC, 0x0CBC }, {
            0x0CBF, 0x0CBF
        }, { 0x0CC6, 0x0CC6 }, { 0x0CCC, 0x0CCD }, {
            0x0D41, 0x0D43
        }, { 0x0D4D, 0x0D4D }, { 0x0DCA, 0x0DCA }, {
            0x0DD2, 0x0DD4
        }, { 0x0DD6, 0x0DD6 }, { 0x0E31, 0x0E31 }, {
            0x0E34, 0x0E3A
        }, { 0x0E47, 0x0E4E }, { 0x0EB1, 0x0EB1 }, {
            0x0EB4, 0x0EB9
        }, { 0x0EBB, 0x0EBC }, { 0x0EC8, 0x0ECD }, {
            0x0F18, 0x0F19
        }, { 0x0F35, 0x0F35 }, { 0x0F37, 0x0F37 }, {
            0x0F39, 0x0F39
        }, { 0x0F71, 0x0F7E }, { 0x0F80, 0x0F84 }, {
            0x0F86, 0x0F87
        }, { 0x0F90, 0x0F97 }, { 0x0F99, 0x0FBC }, {
            0x0FC6, 0x0FC6
        }, { 0x102D, 0x1030 }, { 0x1032, 0x1032 }, {
            0x1036, 0x1037
        }, { 0x1039, 0x1039 }, { 0x1058, 0x1059 }, {
            0x1160, 0x11FF
        }, { 0x1712, 0x1714 }, { 0x1732, 0x1734 }, {
            0x1752, 0x1753
        }, { 0x1772, 0x1773 }, { 0x17B4, 0x17B5 }, {
            0x17B7, 0x17BD
        }, { 0x17C6, 0x17C6 }, { 0x17C9, 0x17D3 }, {
            0x17DD, 0x17DD
        }, { 0x180B, 0x180D }, { 0x18A9, 0x18A9 }, {
            0x1920, 0x1922
        }, { 0x1927, 0x1928 }, { 0x1932, 0x1932 }, {
            0x1939, 0x193B
        }, { 0x200B, 0x200F }, { 0x202A, 0x202E }, {
            0x2060, 0x2063
        }, { 0x206A, 0x206F }, { 0x20D0, 0x20EA }, {
            0x302A, 0x302F
        }, { 0x3099, 0x309A }, { 0xFB1E, 0xFB1E }, {
            0xFE00, 0xFE0F
        }, { 0xFE20, 0xFE23 }, { 0xFEFF, 0xFEFF }, {
            0xFFF9, 0xFFFB
        }, { 0x1D167, 0x1D169 },
        { 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B }, { 0x1D1AA, 0x1D1AD }, {
            0xE0001, 0xE0001
        }, { 0xE0020, 0xE007F },
        { 0xE0100, 0xE01EF }
    };

    /* test for 8-bit control characters */
    if (ucs == 0)
        return 0;
    if (ucs < 32 || (ucs >= 0x7f && ucs < 0xa0))
        return -1;

    /* binary search in table of non-spacing characters */
    if (bisearch(ucs, combining,
                 sizeof(combining) / sizeof(struct interval) - 1))
        return 0;

    /* if we arrive here, ucs is not a combining or C0/C1 control character */

    return 1
           + (ucs >= 0x1100
              && (ucs <= 0x115f || /* Hangul Jamo init. consonants */
                  ucs == 0x2329 || ucs == 0x232a
                  || (ucs >= 0x2e80 && ucs <= 0xa4cf && ucs != 0x303f)
                  || /* CJK ... Yi */
                  (ucs >= 0xac00 && ucs <= 0xd7a3) || /* Hangul Syllables */
                  (ucs >= 0xf900 && ucs <= 0xfaff) || /* CJK Compatibility Ideographs */
                  (ucs >= 0xfe30 && ucs <= 0xfe6f) || /* CJK Compatibility Forms */
                  (ucs >= 0xff00 && ucs <= 0xff60) || /* Fullwidth Forms */
                  (ucs >= 0xffe0 && ucs <= 0xffe6)
                  || (ucs >= 0x20000 && ucs <= 0x2fffd)
                  || (ucs >= 0x30000 && ucs <= 0x3fffd)));
}

int mk_wcswidth(const wchar_t *pwcs, size_t n)
{
    int w, width = 0;

    for (; *pwcs && n-- > 0; pwcs++)
        if ((w = mk_wcwidth(*pwcs)) < 0)
            return -1;
        else
            width += w;

    return width;
}

/*
 * The following functions are the same as mk_wcwidth() and
 * mk_wcwidth_cjk(), except that spacing characters in the East Asian
 * Ambiguous (A) category as defined in Unicode Technical Report #11
 * have a column width of 2. This variant might be useful for users of
 * CJK legacy encodings who want to migrate to UCS without changing
 * the traditional terminal character-width behaviour. It is not
 * otherwise recommended for general use.
 */
int mk_wcwidth_cjk(wchar_t ucs)
{
    /* sorted list of non-overlapping intervals of East Asian Ambiguous
     * characters, generated by "uniset +WIDTH-A -cat=Me -cat=Mn -cat=Cf c" */
    static const struct interval ambiguous[] = { { 0x00A1, 0x00A1 }, {
            0x00A4,
            0x00A4
        }, { 0x00A7, 0x00A8 }, { 0x00AA, 0x00AA },
        { 0x00AE, 0x00AE }, { 0x00B0, 0x00B4 }, { 0x00B6, 0x00BA }, {
            0x00BC, 0x00BF
        }, { 0x00C6, 0x00C6 }, { 0x00D0, 0x00D0 }, {
            0x00D7, 0x00D8
        }, { 0x00DE, 0x00E1 }, { 0x00E6, 0x00E6 }, {
            0x00E8, 0x00EA
        }, { 0x00EC, 0x00ED }, { 0x00F0, 0x00F0 }, {
            0x00F2, 0x00F3
        }, { 0x00F7, 0x00FA }, { 0x00FC, 0x00FC }, {
            0x00FE, 0x00FE
        }, { 0x0101, 0x0101 }, { 0x0111, 0x0111 }, {
            0x0113, 0x0113
        }, { 0x011B, 0x011B }, { 0x0126, 0x0127 }, {
            0x012B, 0x012B
        }, { 0x0131, 0x0133 }, { 0x0138, 0x0138 }, {
            0x013F, 0x0142
        }, { 0x0144, 0x0144 }, { 0x0148, 0x014B }, {
            0x014D, 0x014D
        }, { 0x0152, 0x0153 }, { 0x0166, 0x0167 }, {
            0x016B, 0x016B
        }, { 0x01CE, 0x01CE }, { 0x01D0, 0x01D0 }, {
            0x01D2, 0x01D2
        }, { 0x01D4, 0x01D4 }, { 0x01D6, 0x01D6 }, {
            0x01D8, 0x01D8
        }, { 0x01DA, 0x01DA }, { 0x01DC, 0x01DC }, {
            0x0251, 0x0251
        }, { 0x0261, 0x0261 }, { 0x02C4, 0x02C4 }, {
            0x02C7, 0x02C7
        }, { 0x02C9, 0x02CB }, { 0x02CD, 0x02CD }, {
            0x02D0, 0x02D0
        }, { 0x02D8, 0x02DB }, { 0x02DD, 0x02DD }, {
            0x02DF, 0x02DF
        }, { 0x0391, 0x03A1 }, { 0x03A3, 0x03A9 }, {
            0x03B1, 0x03C1
        }, { 0x03C3, 0x03C9 }, { 0x0401, 0x0401 }, {
            0x0410, 0x044F
        }, { 0x0451, 0x0451 }, { 0x2010, 0x2010 }, {
            0x2013, 0x2016
        }, { 0x2018, 0x2019 }, { 0x201C, 0x201D }, {
            0x2020, 0x2022
        }, { 0x2024, 0x2027 }, { 0x2030, 0x2030 }, {
            0x2032, 0x2033
        }, { 0x2035, 0x2035 }, { 0x203B, 0x203B }, {
            0x203E, 0x203E
        }, { 0x2074, 0x2074 }, { 0x207F, 0x207F }, {
            0x2081, 0x2084
        }, { 0x20AC, 0x20AC }, { 0x2103, 0x2103 }, {
            0x2105, 0x2105
        }, { 0x2109, 0x2109 }, { 0x2113, 0x2113 }, {
            0x2116, 0x2116
        }, { 0x2121, 0x2122 }, { 0x2126, 0x2126 }, {
            0x212B, 0x212B
        }, { 0x2153, 0x2154 }, { 0x215B, 0x215E }, {
            0x2160, 0x216B
        }, { 0x2170, 0x2179 }, { 0x2190, 0x2199 }, {
            0x21B8, 0x21B9
        }, { 0x21D2, 0x21D2 }, { 0x21D4, 0x21D4 }, {
            0x21E7, 0x21E7
        }, { 0x2200, 0x2200 }, { 0x2202, 0x2203 }, {
            0x2207, 0x2208
        }, { 0x220B, 0x220B }, { 0x220F, 0x220F }, {
            0x2211, 0x2211
        }, { 0x2215, 0x2215 }, { 0x221A, 0x221A }, {
            0x221D, 0x2220
        }, { 0x2223, 0x2223 }, { 0x2225, 0x2225 }, {
            0x2227, 0x222C
        }, { 0x222E, 0x222E }, { 0x2234, 0x2237 }, {
            0x223C, 0x223D
        }, { 0x2248, 0x2248 }, { 0x224C, 0x224C }, {
            0x2252, 0x2252
        }, { 0x2260, 0x2261 }, { 0x2264, 0x2267 }, {
            0x226A, 0x226B
        }, { 0x226E, 0x226F }, { 0x2282, 0x2283 }, {
            0x2286, 0x2287
        }, { 0x2295, 0x2295 }, { 0x2299, 0x2299 }, {
            0x22A5, 0x22A5
        }, { 0x22BF, 0x22BF }, { 0x2312, 0x2312 }, {
            0x2460, 0x24E9
        }, { 0x24EB, 0x254B }, { 0x2550, 0x2573 }, {
            0x2580, 0x258F
        }, { 0x2592, 0x2595 }, { 0x25A0, 0x25A1 }, {
            0x25A3, 0x25A9
        }, { 0x25B2, 0x25B3 }, { 0x25B6, 0x25B7 }, {
            0x25BC, 0x25BD
        }, { 0x25C0, 0x25C1 }, { 0x25C6, 0x25C8 }, {
            0x25CB, 0x25CB
        }, { 0x25CE, 0x25D1 }, { 0x25E2, 0x25E5 }, {
            0x25EF, 0x25EF
        }, { 0x2605, 0x2606 }, { 0x2609, 0x2609 }, {
            0x260E, 0x260F
        }, { 0x2614, 0x2615 }, { 0x261C, 0x261C }, {
            0x261E, 0x261E
        }, { 0x2640, 0x2640 }, { 0x2642, 0x2642 }, {
            0x2660, 0x2661
        }, { 0x2663, 0x2665 }, { 0x2667, 0x266A }, {
            0x266C, 0x266D
        }, { 0x266F, 0x266F }, { 0x273D, 0x273D }, {
            0x2776, 0x277F
        }, { 0xE000, 0xF8FF }, { 0xFFFD, 0xFFFD }, {
            0xF0000, 0xFFFFD
        }, { 0x100000, 0x10FFFD }
    };

    /* binary search in table of non-spacing characters */
    if (bisearch(ucs, ambiguous,
                 sizeof(ambiguous) / sizeof(struct interval) - 1))
        return 2;

    return mk_wcwidth(ucs);
}

int mk_wcswidth_cjk(const wchar_t *pwcs, size_t n)
{
    int w, width = 0;

    for (; *pwcs && n-- > 0; pwcs++)
        if ((w = mk_wcwidth_cjk(*pwcs)) < 0)
            return -1;
        else
            width += w;

    return width;
}
